针对贯通式同相自耦变压器(AT)牵引供电系统牵引网边界对高频暂态量有较强的衰减作用，提出一种基于形态学的贯通式同相AT牵引供电系统牵引网单端电流方向暂态保护方法。采用多分辨形态梯度处理保护安装处检测到的故障暂态电流，得到其线模分量波形突变点的极性，由此构成方向起动元件。若极性为负，判定为本侧区外故障，保护不动作。若极性为正，则需进一步对故障电流线模分量进行形态谱运算，并将归一化后的形态谱变换到频域，比较频域下形态谱值与阈值的大小判断是区内或对侧区外故障。利用PSCAD仿真平台对贯通式同相AT牵引供电系统进行建模，针对不同故障条件进行大量仿真，仿真结果验证了保护方法的有效性。

Aiming at the fact that the traction network boundary of the through-type co-phase auto-transformer (AT) traction power supply system has a strong attenuation effect on high-frequency transients, a single-ended current direction transient protection method of traction network based on morphology is proposed. The multi-resolution morphological gradient is used to process the fault transient current detected at the protection installation, and the polarity of the mutation point of the line mode component is obtained, which constitutes the directional start element. If the polarity is negative, the fault occurs outside the local area, and the protection does not operate. If the polarity is positive, it is necessary to further calculate the morphological spectrum of the fault current line mode component, and convert the normalized morphological spectrum to the frequency domain. By comparing the size of the morphological spectrum value and the threshold in the frequency domain, the fault is judged to be an internal fault or an external fault on the opposite side. The through-type co-phase AT traction power supply system is built on PSCAD, and plenty of fault simulations are conducted for different situations. The simulation results show the availability of the protection method.

国家自然科学基金项目（51767012）